Answer:
D. 1.33 segundos.
Explanation:
El cuerpo es experimenta un movimiento en caída libre al modificarse su velocidad por efecto de la gravitación terrestre. Este cuerpo alcanza instantáneamente el reposo cuando se encuentra a su altura máxima, el tiempo puede obtenerse sabiendo la aceleración y las velocidades incial y final a partir de la siguiente ecuación cinemática:
Donde:
- Velocidad final del cuerpo, medida en metros por segundo.
- Velocidad inicial del cuerpo, medida en metros por segundo.
- Aceleración gravitacional, medida en metros por segundo al cuadrado.
- Tiempo, medido en segundos.
Ahora se despeja el tiempo:
Si 
, 
y 
, entonces:
Por ende, la respuesta correcta es D.
Answer:
The child will take 5.952 seconds to travel from the top of the hill to the bottom.
Explanation:
Given that the child accelerates uniformly and that both initial () and final speeds (
), measured in meters per second, and acceleration (
), measured in meters per square second, are known, we proceed to use the following kinematic equation to determine the time taken to travel from the top of the hill to the bottom (), measured in seconds, is:
(1)
If we know that 
, 
and 
, then the time taken is:
The child will take 5.952 seconds to travel from the top of the hill to the bottom.
Answer:
The prediction for its maximum potential energy is 109,375 J
Explanation:
Given;
mass of the coaster car, m = 350 kg
speed of the coaster car at the lowest point, v = 25 m/s
The coaster car will have maximum kinetic energy at the lowest point and based on law of conservation of mechanical energy, the maximum kinetic energy of the coaster car at the lowest point will be equal to maximum potential energy at the highest point.
Therefore, the prediction for its maximum potential energy is 109,375 J
Answer:
change in entropy is 1.44 kJ/ K
Explanation:
from steam tables
At 150 kPa
specific volume
Vf = 0.001053 m^3/kg
vg = 1.1594 m^3/kg
specific entropy values are
Sf = 1.4337 kJ/kg K
Sfg = 5.789 kJ/kg
initial specific volume is calculated as
FROM STEAM Table
at 200 kPa
specific volume
Vf = 0.001061 m^3/kg
vg = 0.88578 m^3/kg
specific entropy values are
Sf = 1.5302 kJ/kg K
Sfg = 5.5698 kJ/kg
constant volume so
Change in entropy 
=3( 3.36035 - 2.88) = 1.44 kJ/kg
